Forming apparatus



March 11, 1969 H K ET AL 3,431,759

FORMING APPARATUS Sheet of 5 Filed Feb. 2. 1966 mi .610 wmM/W a w I. 2%; Z 2 a 7 5% M y March 11, 1969 KlDERA ET AL 3,431,759

FORMING APPARATUS Filed Feb. 2, 1966 I I Sheet 2 of 5 J (D /7 J4! 2A i (O H J; 1 3, f

)5 /7 3'4 14 /4 ILNVENT 125.

United States Patent 13 Claims ABSTRACT OF THE DISCLOSURE A program controlled manipulator is provided With jaws to grip a pipe to be bent, position it in and remove it from a pipe bender, and has six degrees of freedom for grasping or positioning the pipe in various positions.

This invention relates to a forming apparatus and more particularly to a pipe bending machine for automatically forming a succession of bends in a pipe.

Press type pipe bending machines for high production forming of a great variety of pipes, such as automotive exhaust pipes, are well known. These machines form a succession of different shape bends at varying locations in the pipe so that it will fit the underbody contour of the automobile. The machines heretofore proposed for this purpose have been manually operated. That is, an operator has been required to position the pipe with respect to the bending dies of the bending machine for each bend. The axial locations of the bends along the length of the pipe are determined by abutting the pipe end against a series of end stops which are intended to accurately locate the pipe for the respective bending operations. Furthermore, the rotational positions of the planes of each of the respective bends relative to the pipe axis are determined by abutting some portion of the previously bent length of the pipe against a series of devices called trees. This type of bending operation has several disadvantages. The use of the end stops and the trees requires a large amount of setup for each production run and is very costly. In addition, the operators time involved in the manual operation adds greatly to the cost.

It is, therefore, a principal object of this invention to provide an automatic pipe forming machine which requires relatively low cost setup and in which the pipe is automatically positioned in the correct location with respect to the bending machine.

It is a further object of this invention to provide an interconnected pipe handling manipulator and a pipe bender that form a succession of different bends in a pipe.

It is another object of this invention to provide an improved method of automatically forming a series of bends in a pipe.

It is a yet further object of the invention to provide a method for performing a series of bends in a pipe utilizing the bending press as a holding device for the pipe.

A pipe bending machine embodying this invention comprises a pipe bender programmable to perform a succession of different bends in a pipe. A programmable manipulator is positioned adjacent the pipe bender and is adapted to grasp the pipe and position the pipe in a succession of different locations relative to the pipe bender. Control means interrelate the pipe bender and the manipulator for successively positioning a pipe in the pipe bender, bending the pipe and repositioning the pipe.

Other objects and advantages of this invention will become more apparent when considered in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a top plan view of a pipe forming machine embodying the invention;

Patented Mar. 11, 1969 FIGURE 2 is a top plan view, in part similar to FIG- URE 1, showing the pipe bending manipulator in another position;

FIGURES 3 to 6 are perspective views showing the pipe forming apparatus in a series of different positions during a forming operation; and

FIGURE 7 is a schematic view of the control circuit for the pipe forming machine.

Referring now in detail to the drawings and in particu lar to FIGURES 1 and 2, the pipe forming machine is comprised of a pipe bender 11, which may be of any known press type, and a manipulator 12 that is adapted to grasp a pipe and selectively position it within the pipe bender 11. The pipe being bent is identified by the reference numeral 13 in the drawings.

The manipulator 12 is comprised of a head 14 that is supported at the outer end of an arm 15, which arm defines a first axis 16. The arm 15 is telescopic so that its length in the direction of the axis 16 and the position of the head 14 may be altered. At the outer end of the arm 15 adjacent the head 14 is a trunnion 17 that defines a second axis 18 which is perpendicularly disposed with respect to the axis 16. The head 14 is pivotal about the axis 18 at the outer end of the arm 15 by the trunnion 17. The support of the head 14 at the outer end of the trunnion 17 also includes a journal so that the head 14 may be rotated about an axis 16a that lies in the same vertical plane as the axis 16 and intersects it at the axis 18. The angle between the axes 16 and 16a depends upon the degree of pivotal movement of the head 14 about the axis 18.

The inner end of the arm 15 is supported by a manipulator head 19 which is rotatable about a vertical axis 21 that lies in the same vertical plane as the axes 16 and 16a. In addition to rotation about the axis 21, the head 19' is pivotal about a horizontal axis 22. that intersects the axis 21 and is perpendicular to the plane containing the axes 16 and 16a and is parallel to the axis 18. Thus, it should be readily apparent that the head 14 has five degrees of movement. It may be rotated about the axis 16a, pivoted about the axis 18, rotated about the axis 21, pivoted about the axis 22 and extended or retracted in the direction of the axis 16. This permits the head 14 to be located at substantially any point with respect to the bending machine 11.

Referring now to FIGURES 3 through 6, the bending machine 11, which is of a well known press type, comprises an upper ram 23 at the lower end of which bending die 24 is provided. The bending die 24 cooperates with a pair of wing dies 25 and 26- in a Wll known manner to form a bend in the pipe 13. If desired, two or more bending and wing dies may be provided adjacent each other to give the machine more versatility.

The pipe 13 is grasped by a jaw assembly, indicated generally by the reference numeral 27 and comprised of a pair of jaws 28 and 29' having surfaces that engage opposite sides of the pipe 13. A pneumatic cylinder 31 is operative to open and close the jaws 28 and 29 and support the jaws at their inner ends. The pneumatic cylinder is carried at the outer end of an arm 32, the inner end of which is clamped to the head 14 by means of C-clamps 33 and 34. It is to be understood that any other suitable mechanism than a pneumatic cylinder may be employed to actuate the jaw assembly 27. In addition, the jaw actuating assembly need not be positioned at the outer end of the arm 32. The jaw assembly 27 is positioned at the end of the arm 32, however, for a reason which will become more apparent as this description proceeds.

Referring now to FIGURE 7, the manipulator 12 is illustrated schematically as including five control devices 35, 36, 37, 38 and 39 which control each degree of movement of the manipulator head 14 and accordingly the position of the jaw assembly 27, as has been previously described. Another control device 40 operates the pneumatic cylinder 31 to selectively open and close the jaws 28 and 29. Each of the control devices 35 through 40 is connected in circuit with a master control device, indicated schematically at 41. The bending press 11 also is provided with a control circuit which, as schematically illustrated, includes' a downward movement control 42 and an upward movement control 43. The control 42 and 43 are also in circuit with the master control 41.

Operation The described apparatus is adapted to select straight pipe 13 from a storage rack (not shown) and selectively position it between the bending die 24 and wing dies 25 and 26 to form the desired shape and location bends within the pipe and thus form a finished exhaust pipe. After the bending operations are complete the manipulator 12 positions the finished exhaust pipe on a storage rack, not shown. Alternatively, the manipulator 12 may grasp a pipe 13 from a pipe forming machine rather than from a storage rack. It is also possible for the pipe to be grasped from some other machine which has previously formed or performed some other operation upon the pipe. In a like manner, after the operations have been performed by the press 11, the pipe 13 may be transferred to some other forming or finishing operation. Various other modifications of the sequence of operations before and after the bending press 11 will suggest themselves to those skilled in the art.

In operation, the master control 41 first operates upon the maipulator controls 35 through 40 to position the jaw assembly 27 in the proper location to engage a pipe 13 and then clamp the jaw assembly 27 around the pipe 13. The manipulator 12 is then actuated by the master control 41 to position the pipe 13 upon the wing dies 25 and 26 (FIGURE 3). While the jaws 28 and 29 still remain engaged with the pipe 13, the press 11 is energized with the ram 23 and bending die 24 moving downwardly until the pipe 13 is engaged. The master control 41 then energizes the cylinder 31 through the control 40 and causes the jaws 28 and 29 to release their grasp from the pipe 13. The jaw assembly 27 and head 14 then are moved away from the press 11 (FIGURE 4). The master control 41 next energizes the press 11 so that the ram 23 continues its descent the proper amount to place the desired degree of bend in the pipe 13. The manipulator 12 is then re-energized to move to a position at which it can grasp a straight portion of the now bent pipe (FIGURE The position at which the jaw assembly 27 grasps the pipe will determine the location of the pipe with respect to the bending press 11 when the next bending operation takes place. The reason for this will become more apparent as this description proceeds. When the jaws 27 are again in engagement with the bent pipe 13, the press 11 is energized so that the ram 23 moves upwardly and the bending die moves out of engagement with the pipe 13. The wing dies 25 and 26 are held in their deflected position until the bent pipe is removed from the bending press 11 so that they will not interfere with the pipe removal. Once the pipe 13 is removed, the wing dies 25 and 26 are returned to their normal position. The master control 41 then is again energized to move the pipe to the next successive location at which the bend is to be made.

In some instances, a greater degree of movement is required by the manipulator 12 than can be made in one motion. When this occurs, the pipe 13 can be held in an intermediate position by placing it within the Wing dies 25 and 26 and by moving the bending die 24 to the position shown in FIGURE 4 so that it will temporarily hold the pipe until the manipulator 12 can reposition the jaws 27.

In FIGURES 3 through 5 the jaw assembly 27 is shown in engagement with the portion of the pipe 13 to the left hand side of the bending machine 11. In some cases the pipe need be grasped on the right hand side of the bender 11 as shown in FIGURE 6. This is accomplished by rotating the head 14 about the axis 16a and is possible because of the offset of the jaw assembly 27 provided by the arm 32. The relative position of the arm 32 at either side of the bending press 11 is shown in FIGURES 1 and 2 by way of example.

The flexibility of the manipulator 12 permitted by the five degrees of movement previously noted allows the pipe to be grasped in substantially any longitudinal position with respect to the bending press 11. When the bent pipe is repositioned within the dies 24, 25 and 26 of the bending press 11, the axis of the portion positioned with in the dies should lie substantially parallel to the arcuate shape of the dies. This necessity coupled with the fixed location of the base of the manipulator 12 makes it essential that the jaw assembly 27 grasp the pipe 13 at an accurate location, which location will determine the position of the next bend made by the press 11. It is to be understood, of course, that this limitation could be overcome by performing an intermediate holding step upon the pipe, but for maximum efficiency it is desirable to eliminate such intermediate steps.

In addition to altering the position at which the pine is bent along its length, in many applications it is additionally necessary to change the angular position of the pipe between successive bends. This angular adjustment cannot be accomplished with a manipulator having only the noted five degrees of movement unless the jaw assembly 27 is offset from the center line of the bending die 24 with the arm 15 of manipulator 12 perpendicular to the axis of the dies 24, 25 and 26. By offsetting the entire manipulator 12 to one side of the bending machine 11, at least of angular rotation of the pipe may be accomplished. A full 360 rotation is provided, however, by the positioning of the jaw assembly 27 at the end of the arm 32 without any limitation in the reach capabilities of the machine. This full 360 rotation is accomplished by turning the pipe end-for-end to provide an 180 target with the offset arm to the left of dies 24, 25 and 26 and 180 target with the offset arm to the right of dies 24, 25 and 26. This offset arm gives substantially the full equivalent of the provision of a sixth degree of movement, such as could be obtained through the building of an additional wrist action into the manipulator 12 or by making the base of the manipulator movable along a longitudinal axis with respect to the bending press. Such a wrist action would permit rotation about an axis that intersected the axis 16a and was perpendicular to the axes 18 and 16a. In addition to greatly complicating the manipulator 12 and increasing its cost, the building of this additional degree of movement into it might have a tendency to reduce its accuracy.

When the pipe 13 is appropriately repositioned within the press 11 by the manipulator 12 for the next successive bend, the master control 41 again reactivates the press 11 and manipulator 12 for the next bending sequence. As has been previously noted, more than one set of bending dies may be carried by the press 11 so that different radii bends may be formed. The depth of bend also is appropriately controlled by the master control 41 acting through the bending press controls. As has also been previously noted, the pipe 13 may be positioned for the next successive bend either through rotation of the jaw assembly 27 about the axis 16a due to the eccentricity of its support, through a stage of movements with alternative grasping of the pipe 13 between the bending die 23 and wing dies 26 or a combination of these motions.

After the desired contour is formed in the pipe 13, the manipulator 12 is operated by the master control 41 to position the bent pipe 13 upon a storage rack (not shown) or conveyor. As has previously been noted, the bent pipe 13 may be transferred to another forming machine or some mcahining operation rather than being placed upon a storage rack.

While it will be apparent that the preferred embodiments of the invention disclosed are well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What is claimed is:

1. The method of forming at least two bends at different locations in a pipe by means of a bending press and a programmable manipulator comprising the steps of grasping a pipe with the manipulator, positioning the pipe at the desired location within a bending press for one of the bends, actuating the press to bring its bending die into engagement with the pipe, releasing the grasp of the manipulator upon the pipe, and completing the formation of the bend through further movement of the bending die.

2. The method as set forth in claim 1 wherein a second bend is formed in the pipe by regrasping the pipe with the manipulator at the completion of the first bend and before the bending die is returned to its normal position, and repositioning the pipe at the desired second bend location within the press by means of the manipulator.

3. The method as set forth in claim 1 further including the steps of regras-ping the pipe by the manipulator at the completion of the formation of the first bend and before the bending die is returned to its normal position, actuating the press to return its bending die to its normal position, and removing the bent pipe from the press with the manipulator.

4. The method as set forth in claim 3 further including the steps of repositioning the bent pipe in the press subsequent to the formation of the first bend, actuating the press to bring the bending die into engagement with the pipe to hold the pipe in an intermediate position, releasing the grasp of the manipulator upon the pipe, regrasping the pipe with a manipulator in a third location, actuating the press to release the engagement of the bending die with the pipe, and repositioning the pipe in the press in the desired location for a second bend by means of the manipulator.

5. An automatic pipe forming machine comprising a pipe bender programmable to perform at least one bending operation upon a pipe, a programmable manipulator for grasping a pipe, positioning the pipe in the pipe bender and removing the pipe from the pipe bender, and control means for interrelating the operation of said pipe bender and said manipulator for successively positioning a pipe in said pipe bender, bending the pipe and removing the bent pipe from the pipe bender, said manipulator being positionable for grasping the pipe and positioning it in a succession of different locations relative to the pipe bender, said control means interrelating the pipe bender and manipulator for performing a first bend upon the pipe, positioning the pipe in a second location with respect to the pipe bender and forming a second bend upon the pipe prior to final removal from said pipe bender.

6. A automatic pipe forming machine as set forth in claim 5 wherein the pipe bender forms different shape bends in the pipe.

7. An automatic pipe forming machine as set forth in claim 5 wherein the manipulator is positionable for grasping the pipe at differential axial and radial locations.

8. An automatic pipe forming machine comprising a pipe bender programmable to perform at least one bending operation upon a pipe, a programmable manipulator for grasping a pipe, positioning the pipe in the pipe bender and removing the pipe from the pipe bender, and control means for interrelating the operation of said pipe bender and said manipulator for successively positioning a pipe in said pipe bender, bending the pipe and removing the bent pipe from the pipe bender, said pipe bender having a pair of dies adapted to engage the pipe, said control means being operative to bring the dies into engagement with the pipe, release the manipulator from its grasping relationship with the pipe and bend the pipe through further movement of the dies.

9. An automatic pipe forming machine asset forth in claim 8 wherein the control means holds the pipe in the dies during at least one stage of the operation for regrasping the pipe by the manipulator jaws at a different location with subsequent release of the dies without forming a bend in the pipe.

10. An automatic pipe forming machine comprising a pipe bender programmable to perform at least one bending operation upon a pipe, a programmable manipulator for grasping a pipe, positioning the pipe in the pipe bender and removing the pipe from the pipe bender, and control means for interrelating the operation of said pipe bender and said manipulator for successively positioning a pipe in said pipe bender, bending the pipe and removing the bent pipe from the pipe bender, said manipulator having a jaw for grasping the pipe, and means for moving the jaw in at least five degrees of freedom with respect to the pipe bender.

11. An automatic pipe forming machine comprising a pipe bender programmable to .perform at least one bending operation upon a pipe, a programmable manipulator for grasping a pipe, positioning the pipe in the pipe bender and removing the pipe from the pipe bender, and control means for interrelating the operation of said pipe bender and said manipulator for successively positioning a pipe in said pipe bender, bending the pipe and removing the bent pipe from the pipe bender, said manipulator having a jaw for grasping the pipe, and means for moving the jaw in at least the equivalent of six degrees of freedom.

12. An automatic pipe forming machine as set forth in claim 11 wherein the movement of the jaw equivalent to at least one degree of freedom is provided by an arm at one end of which the jaws are supported, the other end of said arm being supported for movement in the remaining degrees of freedom.

13. A manipulator for positioning a pipe with respect to a bending machine, said manipulator comprising a head, an offset arm supported by said head, a pair of jaws supported at the outer end of said arm for grasping a pipe, means for pivoting said head about a first axis, means for pivoting said head about a second axis perpendicular to said first axis, a telescopic arm carrying said head at one end thereof and means for rotating said arm at its other end about two perpendicularly disposed axes.

References Cited UNITED STATES PATENTS 2,864,271 12/ 1958 Kendall 72-42l 3,010,587 11/1961 Hollinger 72405 3,075,568 1/1963 Bright 7234 RICHARD J. HERBST, Primary Examiner.

LOWELL A. LARSON, Assistant Examiner.

US. Cl. X.R. 72-405, 421, 422 

